Creating a new World in 1.8.1 shows some interesting problems. The world looks chopped and not completly generated. Like the chunk A and chuck B dont fit together.
MC-75141
Map Generating Glitch
Resolved
Duplicate
0
Michael Orac
(Unassigned)
Unconfirmed
Minecraft 1.8.1
Retrieved
This issue is a duplicate of MC-315. It has been linked to the original bugreport.
Please search before reporting any bugs, as it's likely that one exists already.